BAIDA, LIBYA - Moammar Gaddafi's son denied Thursday that Libya has killed large numbers of protesters through airstrikes and other attacks, while a former top Gaddafi aide said he quit the government to protest its violent crackdown.

Saif al-Islam Gaddafi, Gaddafi's son, disputed the death tolls that have have been reported since the protests began 10 days ago, saying allegations that hundreds have been killed are a "joke."

"Tripoli is quiet," he said in an interview aired on Libyan state television. "Life is normal."

The junior Gaddafi said Libya intends to provide Western journalists on Friday access to Tripoli, the capital, and other cities, so they can corroborate the government's claim that the country remains under Gaddafi's control.

The U.S. State Department issued a warning to Western journalists who have entered Libya in recent days without government permission. Citing information received from top Libyan officials, the warning said some members of CNN, BBC Arabic and al-Arabiya would be allowed into the country, but any reporters not approved by the government as part of that effort would be considered al-Qaeda "collaborators."

"The Libyan government said that it was not responsible for the safety of these journalists, who risked immediate arrest on the full range of possible immigration charges," the State Department warning said.

Libya appears dangerously fractured, with Gaddafi's regime intent on fighting but its authority beyond Tripoli in doubt. The longtime ruler has tightened his grip on the capital, witnesses say, by flooding the streets with militiamen and loyalist troops who were reportedly roaming the streets and shooting opponents from SUVs.

Rebels who launched an uprising last week have consolidated their control of key eastern cities, however, and continued advancing west across the coastal strip, where most of the country's population is clustered. The opposition has called for a large protest Friday.

In the city of Zawiya, 30 miles west of Tripoli, an army unit attacked a mosque where protesters had been stationed for several days, a witness told the Associated Press. The soldiers opened fire with automatic weapons and hit the mosque's minaret with anti-aircraft missiles, the witness, who spoke on condition of anonymity, said.

He told the AP there were casualties, but couldn't provide exact figures. Some of the young men among the protesters had hunting rifles, he said. He said a day earlier an envoy from Gaddafi had come to the city and warned protesters, "Either leave or you will see a massacre."

"What is happening is horrible, those who attacked us are not the mercenaries; they are sons of our country," the witness said, sobbing. After the assault, thousands massed in the city's main Martyrs Square, shouting "leave, leave," in reference to Gaddafi, he said.

The other attack came at a small airport outside Misrata, Libya's third-largest city, where rebels claimed control on Wednesday, AP reported. Militiamen on Thursday attacked a line of residents who were protecting the facility, opening fire with rocket-propelled grenades and mortars, said a resident who saw the assault